From 9c08dae57d2886fe811e47299d453e47345ad0cf Mon Sep 17 00:00:00 2001
From: ylinzhu <46126022+ylinzhu@users.noreply.github.com>
Date: Tue, 15 Nov 2022 10:03:31 +0800
Subject: [PATCH] fix npe when the frontend connection is closed, the statement
 is still send (#3470)

---
 .../mysql/nio/handler/query/impl/BaseSelectHandler.java       | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/src/main/java/com/actiontech/dble/backend/mysql/nio/handler/query/impl/BaseSelectHandler.java b/src/main/java/com/actiontech/dble/backend/mysql/nio/handler/query/impl/BaseSelectHandler.java
index c062244e6..e34660804 100644
--- a/src/main/java/com/actiontech/dble/backend/mysql/nio/handler/query/impl/BaseSelectHandler.java
+++ b/src/main/java/com/actiontech/dble/backend/mysql/nio/handler/query/impl/BaseSelectHandler.java
@@ -24,6 +24,7 @@ import org.jetbrains.annotations.NotNull;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 
+import java.io.IOException;
 import java.io.UnsupportedEncodingException;
 import java.util.ArrayList;
 import java.util.List;
@@ -48,7 +49,8 @@ public class BaseSelectHandler extends BaseDMLHandler {
 
     public BackendConnection initConnection() throws Exception {
         if (serverSession.closed()) {
-            return null;
+            LOGGER.warn(" FrontendConnection is closed without sending a statement, conn is " + serverSession.getShardingService().getConnection());
+            throw new IOException("FrontendConnection is closed");
         }
 
         BackendConnection exeConn = serverSession.getTarget(rrss);